Firefox 3.5.7 allows for the opening of multiple tabs as the homepage by placing an "|" between each address in the textbox (located in Tools>Options>Main>Startup).

As there are several sites that I frequent on each browser startup, I am able to save much time by having all of the pages already open. I posit that a macro might have already been created for this purpose (forgive my "wide-eyed innocence" in this regard; I am new to K-Meleon, and have taken only minimal C++ in addition to a limited knoweldge of HTML), but consider adding it as a feature if a few others are interested as well, perhaps.